The present invention is directed to a valve for use in draining old transmission oil from an automatic transmission, and for refilling the automatic transmission with new fluid, and a method for using the valve to drain the old fluid and add the new fluid. Current practice of changing automatic transmission oil requires a relatively long and somewhat difficult task, since the vehicle usually must be raised, the transmission pan removed, and the old oil allowed to drip out into container for subsequent disposal. The removal of the pan is the most difficult and time-consuming part of the task. Due to the expense and effort involved, many automatic transmissions are not timely serviced.